Student pilots, keep out

Concern about overcrowded skies has prompted the Federal Aviation Administration to ban solo flights by student pilots at 12 airports.

Andrews Air Force Base

Atlanta Hartsfield

Chicago O'Hare

Dallas-Fort Worth

John F. Kennedy, New York

LaGuardia, New York

Logan, Boston

Los Angeles

Miami

Newark, N.J.

Reagan Washington National

San Francisco

Source: FAA